Many known multiple pattern spray nozzles have complex structures and are relatively expensive to produce. Some, such as the device disclosed in U.S. Pat. No. 4,976,467 (the disclosure of which is incorporated herein by reference), permit spray pattern selection by rotation of a multi-apertured sprayhead to align one of the apertures into the path of the liquid. Many known spray nozzles utilize molded sprayheads.
To create a high-pressure spray pattern, it may be necessary to use an aperture having a small cross-sectional area, requiring close tolerances. It is difficult to form small apertures with close tolerances in a molded sprayhead.
Another disadvantage of known multiple pattern spray nozzles stems from the substitution of plastic for metal in an effort to reduce costs. When debris clogs a nozzle, many users attempt to remove the debris by inserting a paperclip or knife into the clogged aperture. When the aperture is made of plastic, the insertion of a metal object is likely to damage and deform the aperture, permanently changing the resulting spray pattern.
No known design for a multiple pattern spray nozzle allows the small size and close tolerances necessary for creating high-pressure spray patterns in a durable yet affordable product.